[GRASS-dev] PostGIS manager for GRASS GIS
mohit.kumarug08 at students.iiit.ac.in
Thu Apr 5 02:56:19 EDT 2012
Shall I go with this PostGIS manager proposal and apply on melange
Any further suggestions are welcome
Only one day is left to appply.
Thanks and regards,
On Wed, 04 Apr 2012 01:56:17 +0530, Mohit Kumar wrote:
> Hello Martin,
> Sorry couldn't reply earlier as I was stuck with some college work.
> On Mon, 2 Apr 2012 21:00:51 +0200, Martin Landa wrote:
>> 2012/4/2 Mohit Kumar <mohit.kumarug08 at students.iiit.ac.in>:
>>>>> I am interested in making a PostGIS manager in GRASS as a GSoc
>>>>> 2012 task.
>>>>> PyGreSQL is a python module that allows easy use of database
>>>>> from a pyhton script. So it will be like a wrapper over
>>>>> the database. This can be done using wxPython and will be OS
>>>>> Sorry to bug you all, but I am very much interested in developing
>>>> there is new development ongoing for this in GRASS 7, perhaps a
>>>> moment to integrate a manager. Maybe Martin has some insights for
>>>> us over the next days.
>>> Its good to know that development is ongoing for this in GRASS, I
>>> want to work on this as my GSoc task.
>> the current PostGIS-related development in G7 is not much related to
>> this idea. The vector engine in G7 is currently able to read PostGIS
>> geometry data natively without any abstract level (like
>> driver). Also write support has been recently implemented. The
>> implementation is focused on simple feature access, GRASS builds a
>> pseudo-like topology as for OGR links (see v.external). At this
>> I am working on PostGIS topology support in GRASS.
>>> I have made a brief idea for the manager. The following are the
>>> modules of the manager
>>> 1. Setup connection : This module will set up the connection with
>>> the remote
>>> database. It will take the input parameters from user and pass them
>>> to a
>>> connection string. After the connection has been established, the
>>> user will
>>> be shown the various tables(maps) that are stored and other
>>> about the database and the connection
>> This is already available in wxGUI . Of course there is always a
>> space for any kind of improvements. But basically it's already
>> to add widgets for entering username and password is quite easy
>>> 2. View and edit data : This will display the data of the table in
>>> a window
>>> frame. One can view the map and modify the table values or the
>> Also possible in current wxGUI . You just create a link using
>> `v.external` and display the map in the map canvas as normal GRASS
>> vector map. Also direct OGR access  is possible (no links,
>> pseudo-topology built on the fly)
>>> 3. Import to GRASS Data : This gives the user an option to save the
>>> data in
>>> Grass format for further processing/analysis of the data. This also
>>> user an option to discard the data which is of no use.
>> Possible with `v.in.ogr`. Simple wrapper based `v.in.ogr` for
>> importing PostGIS is already there .
>>> 4. Execute PostGis functions (geometry processing)on database and
>>> output in grass data format.
>> This could be improvement.
>>> 5. SQL interface : This provides the advanced user to modify the
>>> database by
>>> use of direct SQL commands on the database.
>>> 6. Export GRASS data to PostGIS data : Convert the Grass Data to
>>> database. First convert the Grass data to Esri Shapefile(.shp)
>>> using OGR and
>>> then converting that data to SQL database (shape2sql).
>> Why?? You can export data directly using `v.out.ogr` . No need
>> Shapefiles, that's bad idea.
>>> 7. Projection support : I was also thinking of adding projection
>>> support to
>>> the manager.
>> In which sense, do you mean on-the fly re-projection (ST_transform)?
>>  http://grass.osgeo.org/wiki/PostGIS#Import_into_GRASS
>>  http://grass.osgeo.org/wiki/PostGIS#Export_to_PostGIS
> Thanks for your feedback.
> I know that various modules are possible in GRASS wxGUI. I want to
> integrate them all and provide a direct interface for them. Regarding
> data Export I was thinking about 'v.out.ogr' only.
> And I was talking about on-the fly re-projection. The projection
> tables can be stored in which ever way the user wants.
> What more would you like to add to the current idea to make it worth
> for a GSOC proposal?
> Looking forward to your support.
> Mohit Kumar (mohitkharb on irc)
> Lab For Spatial Informatics
> International Institute of Information and Technology
> Hyderabad, India
> grass-dev mailing list
> grass-dev at lists.osgeo.org
Mohit Kumar (mohitkharb on irc)
Lab For Spatial Informatics
International Institute of Information and Technology
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